Hierarchy classification:

1. top of the aat hierarchies
2. Materials Facet
3. Materials (hierarchy name)
4. materials (substances)
5. [materials by composition]
6. inorganic material
7. carbon

Anotations

Scope note:

Carbonaceous material, especially charcoal, activated by heat at high temperature, or otherwise treated to increase its porosity and adsorptive power. Activated carbon is used in removal of pollutants from gas and liquids and in other purification processes.